UGREEN Bluetooth 5.0 USB Adapter (Model CM390 / Part Number 80889)
☐ Physical port: Avoid USB 3.0 ports (blue inside). Use USB 2.0 (black/grey). USB 3.0 emits radio noise that kills Bluetooth 2.4GHz signals. ☐ USB Extension cable: If the dongle is plugged into the back of a metal tower PC, use a short USB 2.0 extension cable to bring the adapter into open air. This doubles range. ☐ Disable onboard Bluetooth: If your laptop has built-in Bluetooth, disable it in BIOS or Device Manager. Two active Bluetooth radios will conflict. ☐ Run the official UGREEN tool (Method 4) even if Windows says the driver is installed. It cleans orphaned registry keys. ☐ Restart, don't shut down. Windows Fast Startup often prevents Bluetooth drivers from loading correctly. After install, do a full Restart (not Shutdown + Power on). ugreen bluetooth 50 usb adapter cm390 driver install
When the desktop reloaded, the Bluetooth icon in the taskbar was solid. UGREEN Bluetooth 5
With the correct driver installed, the CM390 demonstrates the capabilities inherent to the Bluetooth 5.0 standard: ☐ USB Extension cable: If the dongle is
Music flowed clean and crisp. Evan leaned back, satisfied. The CM390’s firmware update option in the installer promised better stability; he accepted and let the utility apply the patch. A tiny progress notification climbed slowly, then completed. “Update successful,” it said. Evan felt oddly proud—a small, quiet victory.
If you inserted the dongle and see "Unknown USB Device (Device Descriptor Request Failed)" or nothing happens, you need to follow the manual steps below.